There only seems to be 3 problems with this, all of which are hardly a problem.
The first thing is that the sound cuts off if there is too much blocking the path between the headphones and the transmitter, but it seems like it needs more than your hands and a remote to block it enough to give any static noise.
The second thing is that the transmitter emits the same light a sensor bar does and can cause some confusion for the wii remote, and I do mean "some". I didn't have problems because the sensor bar is on top of my tv and the transmitter is about a foot below my tv. Even if you have problems you can block the light with something small or flip the receiver around(it doesn't seem to hurt the signal). You can check the sensor bar sensitivity settings to see if the lights show up. If they used bluetooth then you'd get much less interference(if any) when in another room or when something big is in the way, but since I use it mainly for playing games I need a clear view of the tv anyway.
The third thing is that it may hurt your ears after playing for a long time. Just take a break for a while and you'll be fine. You're supposed to take a break from gaming after a while anyway.
For use with a DS, it's a better idea to get headphones that can plug in without an adapter(the two plugs are a bit smaller than the port on the DS). It would be too bulky to hook this up to a DS anyway.